The present invention is directed to an improved fitting for receiving and sealing an aerosol cannister.
Aerosol cannisters are widely used as disposable containers for a range of materials. In many applications, these cannisters are used in connection with a mounting bracket which secures the cannister in such a way that a valve fitting on the mounting bracket is sealed against a valve assembly of the cannister. For example, one such application is in connection with devices for injecting an ether based fuel into a diesel engine to improve the cold start characteristics of the engine. Ether based fuel is available in aerosol cannisters, and one type of ether injection device uses a mounting bracket to mount an aerosol cannister which supplies ether based fuel to the engine. Typically, some type of valve actuator is provided to control the release of ether from the cannister through the valve fitting into the engine.
In the past, such mounting brackets have been designed to press the cannister firmly against a gasket in the valve fitting. It is contact with this gasket that seals the valve assembly of the cannister to the valve fitting and retards leakage when ether is discharged out of the cannister into the fitting.
Such gasket type fittings exhibit certain disadvantages. The sealing action of a gasket requires that the cannister be firmly pressed against the gasket, and the mounting bracket used with a gasket type fitting must be relatively substantial and capable of providing the needed sealing force. This may require the use of a heavier and more costly mounting bracket than would otherwise be desirable. Such gasket type fittings may be subject to leakage if adequate sealing force is not constantly applied. For example, the gasket may be gradually deformed by the sealing force to the point where the sealing force is excessively reduced. Moreover, it is often the uppermost, most exposed portion of the aerosol cannister which is pressed against the gasket to provide the seal, and nicks or dents in this exposed surface may prevent the formation of an adequate seal.